Underwater marine cable

ABSTRACT

1. The combination of a new and improved flexible marine cable and a watertight end coupler formed thereon, comprising A MULTISTRAND CENTER CONDUCTOR, A FIRST INNER LAYER OF INSULATION OF HIGH DENSITY POLYETHYLENE SURROUNDING SAID CENTER CONDUCTOR TO PROVIDE GOOD ELECTRICAL INSULATION, A SECOND OUTER LAYER OF INSULATION OF NYLON COVERING SAID INNER LAYER OF INSULATION TO PROVIDE GOOD MECHANICAL STRENGTH, A BRAIDED COAXIAL OUTER CONDUCTOR SURROUNDING THE INSULATION AND SUPPORTED THEREBY, A HIGH DENSITY POLYETHYLENE JACKET ENCASING SAID OUTER CONDUCTOR TO PROVIDE CORROSION PROTECTION AND ABRASION RESISTANCE, A SWAGED ASSEMBLY INCLUDING A COLLAR THROUGH WHICH THE COMBINATION OF SAID OUTER CONDUCTOR, INSULATION, AND CENTER CONDUCTOR PASSES, THE STRANDS OF SAID OUTER CONDUCTOR BEING LAID BACK OVER SAID COLLAR, AND A COLLET SWAGED OVER SAID COLLAR, THE CENTER CONDUCTOR EXTENDING BEYOND SAID SWAGED ASSEMBLY, A GENERALLY CYLINDRICAL CABLE END FITTING HAVING A FIRST AXIAL BORE THERETHROUGH THROUGH WHICH THE COMBINATION OF SAID OUTER CONDUCTOR, INSULATION, AND CENTER CONDUCTOR PASSES, AND A SECOND LARGER DIAMETER AXIAL BORE PART WAY THERETHROUGH WHICH RECEIVES SAID SWAGED ASSEMBLY, A FIRST SEAL COMPRISING A POTTING COMPOUND FILLING THE CAVITY IN SAID SECOND BORE, AND A SECOND SEAL COMPRISING A TAPERED POLYURETHANE SECTION MOLDED OVER SAID END FITTING AND OVER A PORTION OF SAID POLYETHYLENE JACKET ENCASING SAID OUTER CONDUCTOR.

United States Patent Samuel H. Kaufiman Silver Spring, Md.

[72] Inventor [21] Appl.No. 513,126

[22] Filed Dec. 9, 1965 [45] Patented Aug. 24, 1971 [73] Assignee TheUnited States of America as represented by the Secretary of the Navy[54] UNDERWATER MARINE CABLE 5 Claims, 2 Drawing Figs.

[52] U.S.Cl 174/74 R, 174/75 R, 174/77 R, 174/89 [51] Int. Cl H02g 15/02[50] Field of Search 174/73, 74, 75, 76, 77, 85, 89, 90, 93; 339/177;174/74, 75, 77, 89

[56] References Cited UNITED STATES PATENTS 3,074,045 1/1963 Overholser174/89 3,077,513 2/1963 Felts 339/177 3,136,843 6/1964 Pomerantz et a1.339/177 Primary Examiner-Rodney D. Bennett Jr. Assistant Examiner.losephG. Baxter Attorneys-R. S. Sciascia and J. A. Cooke CLAIM: 1. Thecombination of a new and improved flexible marine cable and a watertightend coupler formed thereon, comprising III/IIIIIIIIIIIIIIIII amultistrand center conductor,

a first inner layer of insulation of high density polyethylenesurrounding said center conductor to provide good electrical insulation,

a second outer layer of insulation of nylon covering said inner layer ofinsulation to provide good mechanical strength,

a braided coaxial outer conductor surrounding the insulation andsupported thereby,

a high density polyethylene jacket encasing said outer conductor toprovide corrosion protection and abrasion resistance a swaged assemblyincluding a collar through which the combination of said outerconductor, insulation, and center conductor passes, the strands of saidouter conductor being laid back over said collar, and a collet swagedover said collar, the center conductor extending beyond said swagedassembly,

a generally cylindrical cable end fitting having a first axial boretherethrough through which the combination of said outer conductor,insulation, and center conductor passes, and a second larger diameteraxial bore part way therethrough which receives said swaged assembly,

a first seal comprising a potting compound filling the cavity in saidsecond bore, and

I a second seal comprising a tapered polyurethane section molded oversaid end fitting and over a portion of said polyethylene jacket encasingsaid outer conductor.

ATENTED M1824 ms INVENTOR Samuel H. Kauffman BY M/T TOZNEY AGENTUNDERWATER MARINE CABLE The invention described herein may bemanufactured and used by or for the Government of the United States ofAmerica for governmental purposes without the payment of any royaltiesthereon or therefor.

This invention relates generally to underwater marine cables, and moreparticularly to a new and improved flexible marine cable havingwatertight end couplers formed thereon.

The usual construction for electrical cables required to carrysubstantial mechanical loads is a double-armored, counterwoundconstruction. This construction, however, is too inflexible for manyapplications.

It is therefore an object of the instant invention to provide animproved marine cable which is capable of sustaining high mechanicalloads and withstanding severe flexing without impairing the conductor orthe conductor insulation.

It is another object of this invention to provide a highly flexibleunderwater electrical cable having end couplers formed thereon whichprovide both mechanical and watertight electrical termination that is afraction of the size of available fittings.

It is a further object of the invention to provide a flexible cable forunderwater use which is able to sustain high mechanical loads forsubstantial periods of time and not leak water at high hydrostaticpressures.

According to the present invention, the foregoing and other objects areattained in a preferred embodiment by providing a coaxial cable formedby a multistrand center conductor, a first insulating layer ofpolyethylene, a layer of nylon for mechanical strength, an outerconductor, and an outer polyethylene jacket for corrosion and abrasionprotection. The ends of the cable are made watertight by means of swagedend fittings sealed by potting material.

The specific nature of the invention, as well as other objects, aspects,uses and advantages thereof, will clearly appear from the followingdescription and from the accompanying drawing, in which:

FIG. 1 is a cross-sectional view of the marine cable and an end coupleraccording to the invention which shows the construction thereof; and

FIG. 2 is an end view of the end coupler shown in FIG. 1.

Referring now to the drawing, and'more particularly to FIG. 1, themarine cable according to the invention comprises an insulated centerconductor which is stranded to promote flexibility. The insulation is intwo layers; an inner layer 102 of high density polyethylene to provideexcellent electrical insulation, and an outer layer 103 of nylon toprovide protection for inner layer 102. A stranded coaxial outerconductor 104 surrounds the insulation and is supported thereby. Outerconductor 104 is preferably made of steel and is the principal strengthmember of the cable. A high density polyethylene jacket 105 encases thecable to provide corrosion protection and abrasion resistance.Alternatively, the abrasion resistance of the cable can be enhanced byusing nylon or polyurethane in place of the high density polyethylenefor jacket 105.

The end coupler shown in FIGS. 1 and 2 includes a swaged assemblysecured to the cable. This assembly comprises a collar 106 through whichthe cable, except for jacket 105, passes. As is shown in FIG. 1, jacket105 terminates some distance before the end of the cable. The strands ofconductor 104 are untwisted and, uniformly distributed, laid back overcollar 106. A collet 107 is swaged on over the strands of conductor 104and collar 106, the excess wire lengths extending beyond collet 107being trimmed off. The end coupler additionally comprises a generallycylindrical cable end fitting 108. Fitting 108 has a main body portion109, a smaller diameter tail portion 111, and a larger diameter headportion 112. An axial bore having a diameter slightly larger than theswaged assembly including collar 106 and collet 107 extends through thehead 112 and a substantial distance into the main body portion 109 offitting 108. A smaller diameter axial bore slightly larger than thecable without jacket extends through the tail portion 111 of fitting 108and communicates with the larger diameter bore in the body portion 109.The swaged assembly rests on the shoulder formed by the junction of thetwo axial bores, and the cable extends out through the bore in tailportion 111. An axial recess having a slightly larger diameter than thebore receiving the swaged assembly is provided in the face of the headportion 112 of fitting 108. This recess receives an insert 113 whichsupports a central pin connector 114. The central conductor 101 of thecable extends beyond the swaged assembly and is electrically connectedto the base of pin connector 114 as by crimping the conductor into arecess thereof, for example. A second electrical connector in the formof an annular disk 115 having a plurality of outwardly extending andforwardly projecting tabs 1 16 surrounds pin connector 114 but iselectrically insulated therefrom. As illustrated, disk 115 and insert 113 are provided with a plurality of holes drilled therethrough which arein registry. To provide connection to the outer coaxial conductor 104 ofthe cable, a plurality of uninsulated, soft, coated copper wires 117,less in number than the number of holes in disk 115 and insert 113,extend from the swaged assembly through insert 113 and are bent over andsoldered to disk 115. Preferably, wires 117 are placed between collar106 and collet 107 before the swagging process to ensure a goodelectrical and mechanical connection. The fitting 108 is made watertightby potting the swaged assembly and the extending center conductor in asuitable epoxy resin generally indicated at 118, the cavity in fitting108 being filled through one of the empty holes in disk 115 and insert113. Alternatively, polyurethane may be used as the potting compoundinstead of an epoxy resin. A second seal is provided by molding atapered polyurethane section 119 over the tail portion 111 of fitting108 and the cable including jacket 105. The molded section 119 alsoprotects the cable end against sharp bends. Adhesion between thepolyurethane section 119 and the metal tail portion 111 of fitting 108is mechanically enhanced by providing a collar 121 about tail portion111 a short distance from the main body portion 109. Adhesion is furtherchemically enhanced by priming the surface of tail portion 111 with asuitable primer and flame treating and priming the surface of thepolyethylene cable jacket 105. Polyurethane is used as the moldingmaterial because it can be molded at moderate temperatures F). Elevatedtemperatures, for an appreciable period of time, cause flow of theconductor insulation and allow leakage between the insulation and theepoxy potting. Further, the polyurethane is a good adhesive, tough andabrasion resistant. As an alternative, tapered section 119 may beinjection molded using a medium or low density polyethylene. Since thetime required to mold is short the heat does not destroy the bondbetween the epoxy and the center conductor insulation.

The end coupler is secured to a connector (not shown) by means of asecuring threaded cap 122. Cap 122 is conjoined to the head portion 112of fitting 108, extending about the periphery thereof, and may, asillustrated, extend over the shoulder formed between head portion 112and main body portion 109 of fitting 108. Alternatively, securing cap122 may be integrally formed on head portion 112. The seal between theend coupler and another connector to which the coupler is secured ismade by O-ring 123 which is supported in an annular groove in the faceof head portion 112 near the outer edge thereof.

It will be apparent that the embodiment shown is only exemplary and thatvarious modifications can be made in construction and arrangement withinthe scope of the invention as defined in the appended claims.

I claim as my invention:

1. The combination of a new and improved flexible marine cable and awatertight end coupler formed thereon, comprismg a multistrand centerconductor,

a first inner layer of insulation of high density polyethylenesurrounding said center conductor to provide good electrical insulation,

a second outer layer of insulation of nylon covering said inner layer ofinsulation to provide good mechanical strength,

a braided coaxial outer conductor surrounding the insulation andsupported thereby,

a high density polyethylene jacket encasing said outerconductor toprovide corrosion protection and abrasion resistance,

a swaged assembly including a collar through which the combination ofsaid outer conductor, insulation, and center conductor passes, thestrands of said outer conductor being laid back over said collar, and acollet swaged over said collar, the center conductor extending beyondsaid swaged assembly,

a generally cylindrical cable end fitting having a first axial boretherethrough through which the combination of said outer conductor,insulation, and center conductor passes, and a second larger diameteraxial bore part way therethrough which receives said swaged assembly,

a first seal comprising a potting compound filling the cavity in saidsecond bore, and

a second seal comprising a tapered polyurethane section molded over saidend fitting and over a portion of said polyethylene jacket encasing saidouter conductor.

2. A new and improved flexible marine cable as recited in claim 1wherein said end fitting further has an axial recess larger in diameterthan said second bore at the entrance of said second bore, said endcoupler further comprising an insert received by said recess, and

and pin connector supported by said insert and extending therethrough,said center conductor being electrically connected to the base of saidpin connector.

3. A new and improved flexible marine cable as recited in claim 2wherein an annular groove is cut in the end of end fitting around saidrecess, said groove supporting a third seal in the form of an O-ring.

4. A new and improved flexible marine cable as recited in claim 3wherein said potting compound is an epoxy resin.

5. A new and improved flexible marine cable as recited in claim 3wherein said potting compound is polyurethane.

1. The combination of a new and improved flexible marine cable and awatertight end coupler formed thereon, comprising a multistrand centerconductor, a first inner layer of insulation of high densitypolyethylene surrounding said center conductor to provide goodelectrical insulation, a second outer layer of insulation of nyloncovering said inner layer of insulation to provide good mechanicalstrength, a braided coaxial outer conductor surrounding the insulationand supported thereby, a high density polyethylene jacket encasing saidouter conductor to provide corrosion protection and abrasion resistance,a swaged assembly including a collar through which the combination ofsaid outer conductor, insulation, and center conductor passes, thestrands of said outer conductor being laid back over said collar, and acollet swaged over said collar, the center conductor extending beyondsaid swaged assembly, a generally cylindrical cable end fitting having afirst axial bore therethrough through which the combination of saidouter conductor, insulation, and center conductor passes, and a secondlarger diameter axial bore part way therethrough which receives saidswaged assembly, a first seal comprising a potting compound filling thecavity in said second bore, and a second seal comprising a taperedpolyurethane section molded over said end fitting and over a portion ofsaid polyethylene jacket encasing said outer conductor.
 2. A new andimproved flexible marine cable as recited in claim 1 wherein said endfitting further has an axial recess larger in diameter than said secondbore at the entrance of said second bore, said end coupler furthercomprising an insert received by said recess, and and pin connectorsupported by said insert and extending therethrough, said centerconductor being electrically connected to the base of said pinconnector.
 3. A new and improved flexible marine cable as recited inclaim 2 wheRein an annular groove is cut in the end of end fittingaround said recess, said groove supporting a third seal in the form ofan O-ring.
 4. A new and improved flexible marine cable as recited inclaim 3 wherein said potting compound is an epoxy resin.
 5. A new andimproved flexible marine cable as recited in claim 3 wherein saidpotting compound is polyurethane.